It is known to use nematic liquid crystal compounds in electrooptic displays. Such displays can be of various types such as the so-called twisted nematic display and multiplexed display and are utilized in constantly increasing numbers in watches and other instruments. Such displays are well known to those skilled in the art.
One of the problems encountered in the utilization of nematic liquid crystal materials in such displays is the availability of stable low viscosity nematic compounds which are liquid at near room temperature and have relatively low transition temperatures to make them practical for use in electro-optic display devices, Further, it is desirable that the nematic liquid crystal material require the application of a minimal amount of electrical potential to obtain the desired effect in order to minimize the power requirements in the display device. Only a limited number of nematic liquid crystal compounds thus far known possess these desired characteristics.
Two compounds possessing the aforementioned combination of properties are described more fully in U.S. Pat. No. 4,200,580 issued Apr. 29, 1980 and in copending U.S. application Ser. No. 135,855 filed Apr. 13, 1980 of common assignee herewith. Those compounds are represented generally by the formula: ##STR2##
Published Japanese patent application No. 55-85583 (published June 27, 1980) and published U.K. patent application No. 2,041,354A (published Sept. 10, 1980) disclose dioxane compounds having the formula: ##STR3## where X and Y can be a variety of substituents.
Although various liquid crystal admixtures have been developed by prior art workers for twisted nematic and multiplexed displays, there still remains the need for new compounds and admixtures with improved properties for optimum display operation.